[5/6] vhost: fix possible dead loop in vector filling
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Commit Message
Fix a possible dead loop which may happen, e.g. when driver
created a loop in the desc list and lens in descs are zero.
Fixes: fd68b4739d2c ("vhost: use buffer vectors in dequeue path")
Fixes: 2f3225a7d69b ("vhost: add vector filling support for packed ring")
Cc: stable@dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
lib/librte_vhost/virtio_net.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
Comments
On 1/4/19 5:06 AM, Tiwei Bie wrote:
> Fix a possible dead loop which may happen, e.g. when driver
> created a loop in the desc list and lens in descs are zero.
>
> Fixes: fd68b4739d2c ("vhost: use buffer vectors in dequeue path")
> Fixes: 2f3225a7d69b ("vhost: add vector filling support for packed ring")
> Cc: stable@dpdk.org
>
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
> lib/librte_vhost/virtio_net.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
@@ -309,6 +309,7 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
uint16_t vec_id = *vec_idx;
uint32_t len = 0;
uint64_t dlen;
+ uint32_t nr_descs = vq->size;
struct vring_desc *descs = vq->desc;
struct vring_desc *idesc = NULL;
@@ -319,6 +320,10 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
dlen = vq->desc[idx].len;
+ nr_descs = dlen / sizeof(struct vring_desc);
+ if (unlikely(nr_descs > vq->size))
+ return -1;
+
descs = (struct vring_desc *)(uintptr_t)
vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
&dlen,
@@ -348,6 +353,11 @@ fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
return -1;
}
+ if (unlikely(nr_descs-- == 0)) {
+ free_ind_table(idesc);
+ return -1;
+ }
+
len += descs[idx].len;
if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
@@ -510,6 +520,9 @@ fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
if (unlikely(vec_id >= BUF_VECTOR_MAX))
return -1;
+ if (unlikely(*desc_count >= vq->size))
+ return -1;
+
*desc_count += 1;
*buf_id = descs[avail_idx].id;